JP2002120419A - Paper feeding mechanism and image recording device using the paper feeding mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a paper feeding mechanism for certainly conveying various recording media on a platen while preventing lift-up and an imaging device using the paper feeding mechanism. SOLUTION: Rectangular recess parts 40 are formed on the upper surface of a platen 30 by a predetermined interval along the paper conveyance direction so that movable ribs 42 can be stored in the recess parts 40. A coil spring is contacted with the bottom part of the recess parts 40 and the rear surface of the movable ribs 42 for forcing the movable ribs 42 in the direction pushed out from the recess parts 40. As to the spring force of the coil springs, it can be contracted by the self weight of an envelope. Therefore, since the movable ribs 42 are moved downward while conveyance of the envelope, the envelope is conveyed below with respect to a plain paper sheet. Thereby, friction on the nozzle surface 28A of a recording head 28 can be prevented so that breakdown of the recording head 28 by the friction on the nozzle surface 28A can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feed mechanism for feeding a recording medium and an image recording apparatus using the paper feed mechanism.

[0002]

2. Description of the Related Art As a prior art, for example, Japanese Unexamined Patent Publication No.
In the publication No. 9797, as shown in FIG.
A plurality of holes (not shown) are formed on the upper surface of the platen 102 on which the recording medium P to be printed with the ink ejected from 00 is conveyed, and the suction device 104 disposed below the platen 102 The recording medium P is sucked onto the platen 102 surface.

Here, a plurality of ribs 102A extend on the upper surface of the platen 102 along the direction in which the recording medium P is conveyed. For this reason, the recording medium P is conveyed in a state in which it contacts the top surface of the rib 102A.

When ink is ejected on the recording medium P, the recording medium P swells and undulates.
The wavy portion is absorbed by the concave groove 102B located between A.

[0005] On the other hand, the recording medium P includes, for example, plain paper and an envelope, which have different thicknesses, so that the distance between the printing surface and the nozzle surface 100A is different. Therefore, if the height of the rib 102A is determined according to the plain paper,
When the envelope body is conveyed, there is a possibility that the nozzle surface 100A may be rubbed by the portion that has been lifted by the waving,
Further, if the height of the rib 102A is determined according to the envelope, the distance between the plain paper and the nozzle surface becomes longer than necessary, and the accuracy of the image is reduced.

[0006]

SUMMARY OF THE INVENTION In consideration of the above-mentioned facts, the present invention prevents the floating, and maintains the image accuracy irrespective of the type of the recording medium, thereby reliably transporting the recording medium on the platen. It is an object to provide a paper feed mechanism and an image recording apparatus using the paper feed mechanism.

[0007]

According to the first aspect of the present invention, a platen is disposed so as to face a movement locus of a recording head from which ink is ejected, and a recording medium is conveyed by the platen. On the upper surface of the platen, a plurality of fixed ribs and a plurality of movable ribs extend in the direction in which the recording medium is transported, and are arranged at predetermined intervals in a direction orthogonal to the transport direction. When it is pushed, it sinks.

[0008] For this reason, by transporting the envelope body which is thicker than the plain paper on the movable rib, the amount by which the movable rib sinks and the thickness of the envelope body are absorbed.
The nozzle surface of the recording head that slides on the platen can be prevented from rubbing the envelope body, and the failure of the recording head due to the nozzle surface rubbing can be prevented.

Further, by transporting the thick envelope below the plain paper, the distance between the nozzle surface and the printing surface in the height direction can be kept constant. The accuracy of the image quality can be kept constant.

According to the second aspect of the present invention, the movable rib is urged toward the recording head by the urging means, and the amount of movement is limited by the stopper.

According to the third aspect of the present invention, the area where the movable ribs are arranged is substantially equal to the width of the envelope which is one of the recording media. Thus, by minimizing the area of the movable rib, the area of the fixed rib is increased, and the accuracy of the image quality when conveying plain paper is maintained.

According to the fourth aspect of the invention, the fixed ribs are arranged on both sides of the area where the movable ribs are arranged. Thereby, for example, in the case of plain paper, both ends are conveyed by the fixing ribs. For this reason, even if the plain paper slightly bends due to the sinking of the movable rib, the amount of deflection is suppressed to a range where the image quality is not affected by using the stiffness of the plain paper by transporting the both ends with the fixed ribs. be able to.

According to the fifth aspect of the present invention, the registration reference position of the envelope is set to the end of the area where the movable rib is arranged, and the envelope is conveyed in the area where the movable rib is arranged. Thereby, the end of the envelope body is prevented from hanging on the region of the fixing rib.

According to the sixth aspect of the present invention, the top surface of the movable rib and the top surface of the fixed rib are at the same height in a state where the recording medium is not conveyed. Thus, when the plain paper is conveyed, the distance between the nozzle surface of the recording head and the printing surface does not vary between the region of the fixed rib and the region of the movable rib.

According to the present invention, a pair of conveying rollers for nipping and conveying the recording medium is disposed upstream of the platen. Between the transport roller pair and the platen,
A recording medium pressing member for pressing the upper surface of the recording medium to correct the posture and guiding the recording medium to the platen is provided. Thus, the curl of the leading end of the recording medium conveyed from the conveying roller pair is suppressed, and the recording medium is reliably guided to the platen.

According to the eighth aspect of the present invention, the position of the leading end of the recording medium pressing member is set to be 0.2 mm from the top surface of the fixing rib.
０．５0.5 mm higher. Thus, the recording medium can be smoothly guided to the top surface of the fixing rib.

Further, since the thickness of the plain paper is about 0.1 mm and the thickness of the envelope is about 2 mm, the height difference between the recording medium pressing member and the top surface of the fixing rib is 0.2 mm to 0 mm. .
By setting it to 5 mm, in the case of plain paper, the leading end can be prevented from curling toward the recording head,
In the case of the envelope, the recording medium pressing member can reliably press the envelope against the platen.

According to the ninth aspect of the present invention, a plurality of suction holes are provided on the upper surface of the platen so as to face the movement trajectory of the nozzle surface provided on the recording head. The medium is being sucked.

Therefore, the recording medium conveyed on the platen is sucked through the suction holes and conveyed while being in contact with the top surface of the fixing rib, so that the printing surface of the recording medium and the nozzle surface of the recording head are Is always constant. Therefore, the printed image is not disturbed.

Further, even if the surface of the recording medium swells and undulates due to the ink ejected to the recording medium, the ink is sucked into the upper surface of the platen by the suction means. It is absorbed by the height difference from the upper surface of the platen. Therefore, the recording medium does not rise to the recording head side, so that the nozzle surface is not rubbed by the recording medium.

In the case of an envelope, since it is conveyed in the area where the movable rib is arranged, it is conveyed in contact with the upper surface of the platen. Therefore, compared to the case where the sheet is transported in a state in which it is in contact with the top surface of the fixing rib, the suction force is increased,
The lifting of the recording medium can be suppressed.

According to the tenth aspect of the present invention, the urging means is a spring, and the movable rib has a spring force that sinks when the envelope is conveyed. Thus, the mechanism is simple because the movable rib can be sunk only by using the spring as the urging means. On the other hand, the stopper is integrally formed with a movable rib protruding from a long hole formed on the platen surface, and abuts on the back surface of the platen to limit the amount of movement of the movable rib.

According to the eleventh aspect of the invention, the urging means is a spring, and the movable rib has a spring force such that the movable rib sinks through the envelope by the pressing force of the recording medium pressing member.

As described above, by transmitting the pressing force of the recording medium pressing member to the movable rib through the envelope, the movable rib is prevented from sinking by plain paper which is less stiff than the envelope.

In the twelfth aspect of the present invention, the upper surface of the platen in the area where the movable ribs are arranged is more distant from the nozzle surface of the recording head than the upper surface of the platen in the area where the fixed ribs are arranged.

Since the envelope body is thicker than plain paper, the upper surface of the platen in the region of the movable rib is separated from the nozzle surface more than the upper surface of the platen in the region of the fixed rib to secure the sinking amount of the movable rib. Then, the thickness of the envelope is absorbed. This prevents the nozzle surface from sliding on the envelope when the envelope is transported.

According to a thirteenth aspect of the present invention, the image recording apparatus includes the paper feed mechanism according to any one of the first to eleventh aspects.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a paper feeder 10 having a paper feed mechanism according to this embodiment will be described.

As shown in FIGS. 1 and 2, a sheet (plain paper, envelope, etc.) as a recording medium inserted from an insertion slot 11 is fed to a transport path 12 provided in an ink jet recording apparatus (not shown). Through the paper feeder 10. A transport roller 14 is rotatably supported on the side plate 10A of the paper feeder 10, and a driving force is transmitted by a driving unit (not shown) to transport the paper.

With the conveyance path 12 therebetween, the conveyance rollers 14
A pinch roller 16 is provided at a position facing the above. The pinch roller 16 is supported by a plurality of shafts 18 at a predetermined distance from each other and can be driven by the transport roller 14.

Here, from the rear plate 10B of the paper feeder 10, a plate-like paper pressing member 2
0 is overhanging. The paper pressing member 20 is located above the pinch roller 16 and the paper pressing member 20
An arc-shaped pinch roller escape portion 22 is recessed on the back surface of the pinch roller.
Is arranged.

Further, a through hole 24 is provided in each sheet pressing member 20 along the sheet conveying direction, and a shaft 18 of the pinch roller 16 is located behind the through hole 24.

On the other hand, one end of a fan 26 spreading in a fan shape is fixed to the back plate 10 B of the paper feeder 10, and the other end of the spring 26 passes through the through hole 24 and contacts the shaft 18. ing.

The spring 26 is urged in a direction in which one end and the other end push the spring 26 around the main part 26A. By fixing one end of the spring 26, the other end is required. An urging force in a direction away from the one end portion around the portion 26A is obtained.

That is, the shaft 18 is connected to the spring 26
Abutting the other end thereof, a nip force is obtained between the pinch roller 16 and the transport roller 14, and the sheet can be nipped and transported.

On the other hand, the axis of the pinch roller 16 is located slightly downstream of the axis of the transport roller 14. Thus, the leading end of the conveyed sheet is guided below the position of the conveyance path 12. Therefore, the leading end of the conveyed sheet is prevented from curling toward the nozzle surface 28A (upward) of the recording head 28 disposed downstream of the sheet pressing member 20.

Here, a guide rail (not shown) is disposed above the paper pressing member 20 at right angles to the paper transport direction, and is fixed to the side plate 10A of the paper feeder 10. A carriage (not shown) on which the recording head 28 is mounted is attached to the guide rail, and is slidable along the guide rail.

The carriage holds a recording head 28. Ink is ejected from a nozzle surface 28A provided at the tip of the recording head 28, and adheres to the conveyed paper to print pictures and characters. Becomes possible.

A platen 30 is provided at a position facing the movement trajectory of the recording head 28, and a sheet is conveyed on the platen 30. A guide surface 32 is provided on the side of the sheet pressing member 20 of the platen 30 and is inclined obliquely downward toward the conveying roller 14. When the leading end of the sheet comes into contact with the sheet, the sheet follows the guide surface 32 and the platen 30 follows. 30 is guided to the upper surface.

On the upper surface of the platen 30, a plurality of fixed ribs 36 and movable ribs 42 are extended in the sheet transport direction, and the fixed ribs 36 and the movable ribs 42 are arranged at predetermined intervals in a direction orthogonal to the transport direction. Have been.

As shown in FIGS. 3 and 4, the movable rib area 38 in which the plurality of movable ribs 42 are arranged has rectangular recesses 40 (at predetermined intervals in a direction orthogonal to the sheet transport direction). An elongate hole) is formed in the recess, and the depth of the recess 40 is slightly larger than the thickness of the movable rib 42 and the substantially prism-shaped pedestal 41 on which the movable rib 42 protrudes.

The length of the peripheral wall of the concave portion 40 is
The base 41 is slightly longer than the peripheral wall of
The movable rib 42 is accommodated in a state where it is sunk from the platen surface 30 </ b> A located on the upper surface of the platen 30 with a gap provided between the movable rib 42 and the peripheral wall of the platen 30.

At both ends of the bottom of the recess 40, mounting holes 44 are provided.
Are provided, and engagement pieces 46 project toward the inside of each other at the edges of the mounting holes 44. on the other hand,
Elastic pieces 48 hang down from both ends of the rear surface of the pedestal 41, and the elastic pieces 48 are large enough to be inserted into the mounting holes 44.

The claw portion 50 protrudes outward from the distal end portion of the elastic piece 48, and the distance between the distal end portions 50A of the claw portion 50 is the distance between the distal end surfaces 46A of the engaged pieces 46. Narrower than.

Therefore, when the elastic piece 48 is inserted into the mounting hole 44, the base 50B of the claw 50 slides on the distal end surface 46A of the engaged piece 46, and the claw 50 moves toward the distal end 50A. The elastic piece 48 is gradually elastically deformed. Claw part 5
When the leading end 50A of the zero is over the lower edge of the leading end surface 46A of the engaged piece 46, the claw 50 is restored, and as a result, the claw 5
0 becomes engageable with the engaged piece 46.

On the other hand, the separation distance from the back surface of the pedestal 41 to the tip end surface 46A of the claw portion 50 is longer than the thickness of the engaged piece 46, and the claw portion 50 engages with the engaged piece 46. (The claw portion 50 abuts on the back surface of the engaged piece 46), and then the movable rib 4
2 is movable downward in the recess 40.

Here, a pair of mounting portions 52 are formed in the bottom surface of the concave portion 40, and one end of a coil spring 54 as an urging means is mounted on the mounting portions 52. The other end of the coil spring 54 is mounted on a mounting portion 56 protruding from the rear surface of the pedestal 41 and urges the movable rib 42 in a direction to push it out of the recess 40. By the urging force of the coil spring 54, the claw portion 50 engages with the engaged piece 46 (the claw portion 50 contacts the back surface of the engaged piece 46).

Therefore, when the movable rib 42 is pressed in the direction against the urging force of the coil spring 54 via the movable rib 42, the movable rib 42 is housed in the concave portion 40 and sinks below the platen surface 30A, and when the pressing force is released. The movable rib 42 protrudes from the platen surface 30A. At this time, the claw portion 50 is engaged with the engaged piece 46, and the amount of movement of the movable rib 42 is limited.

In this state, the height of the top surface of the movable rib 42 is substantially the same as the height of the top surface of the fixed rib 36. Thereby, as shown in FIG. 5, when the plain paper 43 is conveyed, the nozzle surface 28A of the recording head 28 that slides above the platen 30 and the printing surface in the area of the fixed rib 36 and the area of the movable rib 42 The distance between them is not varied.

Further, as shown in FIG.
8 is substantially the same as the width (transverse direction) of the envelope 45, and the movable rib area 38 conveys the envelope 45. In this way, by minimizing the area of the movable rib 42, the area of the fixed rib 36 is increased, and the image quality when conveying the plain paper 43 (see FIG. 5) is maintained.

Here, as shown in FIGS. 3, 5 and 6, the spring force of the coil spring 54 provided on the movable rib 42 can be contracted by the weight of the envelope 45. Therefore, when the envelope 45 is transported, the movable rib 4
Since 2 sinks, the envelope 45 is conveyed below the plain paper 43.

Since the thickness of the envelope 45 is larger than that of the plain paper 43, the movable rib 42 sinks to absorb the thickness of the envelope 45. Thereby, when the envelope 45 is transported, the nozzle surface 28A of the recording head 28 can be prevented from rubbing, and the failure of the recording head 28 due to the rubbing of the nozzle surface 28A can be prevented.

Further, the movable rib area 38 is
Both ends of the plain paper 43 are conveyed by the fixing ribs 36. Thereby, even if the plain paper 43 is slightly bent due to the sinking of the movable rib 42 by the movable rib area 38, both ends are conveyed by the fixed ribs 36, and the image quality is improved by using the stiffness of the plain paper 43. It is possible to suppress the amount of deflection in a range that does not affect.

The registration reference position Q of the envelope 45 is shifted from the registration reference position P of the plain paper 43 so that the envelope 45 is conveyed in the movable rib area 38 in accordance with the end of the movable rib area 38. . Thereby, the end of the envelope 45 is prevented from being hooked on the fixing rib 36.

As shown in FIG. 2, the leading end 20A of the paper pressing member 20 is sharp, and the position of the leading end 20A is 0.2 mm to 0.5 m above the top surface of the fixing rib 36.
m higher. Thus, the sheet can be smoothly guided to the top surface of the fixing rib 36.

Since the thickness of the plain paper is about 0.1 mm and the thickness of the envelope is about 2 mm, the height difference between the paper pressing member 20 and the top surface of the fixing rib 36 is 0.2 mm to 0.2 mm.
By setting it to 0.5 mm, in the case of plain paper, it is possible to prevent the leading end from curling toward the recording head 28 side.

Specifically, as shown in FIG. 7A, the plain paper 43 is nipped and transported by the transport roller 14 and the pinch roller 16, and is guided to the guide surface 32 as shown in FIG. 7B. You. Even if the leading end of the plain paper 43 is curled as shown by a virtual line, the leading end 20
The movement toward the recording head 28 is regulated by A and guided to the guide surface 32.

As shown in FIG. 5 and FIG. 7C, the plain paper 43 follows the guide surface 32 and
0 and is conveyed in a state of contacting the top surface of the fixed rib 36 and the top surface of the movable rib 42.

On the other hand, as shown in FIGS. 8A and 8B,
In the case of the envelope 45, the transport roller 14 and the pinch roller 16
Is conveyed in a state where the upper surface (printing surface) and the lower surface of the two-ply envelope 45 are in close contact with each other. When the envelope 45 reaches the leading end portion 20A of the paper pressing member 20, the envelope 45 is further pressed down, and the paper pressing member 20 is pressed. 6A and 8C while being guided to the guide surface 32 by the distal end portion 20A of FIG.
As shown in (2), the stiffness of the envelope 45 itself ensures that the movable rib 42 projecting from the platen surface 30A sinks.

As described above, the top surface of the movable rib 42 can be made flush with the platen surface 30A by utilizing the pressing force of the paper pressing member 20. For this reason, the envelope 45
Is transported on the platen surface 30A, as shown in FIG. 6, the paper is transported at a position lower than the position where the plain paper is transported (the top surface of the fixing rib 36), and the nozzle surface 2 of the recording head 28 is
8A does not slide on the upper surface of the envelope 45.

Further, the paper holding member 20 is placed via the envelope 45.
Since the movable rib 42 is made to sink into the concave portion 40 by using the plain paper 43, which is less stiff than the envelope 45.
In this case, the movable rib 42 does not sink by the paper pressing member 20.

On the other hand, on the platen surface 30A, the distance in the height direction from the nozzle surface 28A is changed between the movable rib region 38 and the fixed rib region 34. The distance from the nozzle surface 28A is long. Thereby, the amount of sinking of the movable rib 42 is secured, and the thickness of the envelope 45 is absorbed.
Therefore, the nozzle surface 28A does not rub when the envelope 45 is transported.

As described above, by transporting the thick envelope 45 below the plain paper 43, the nozzle surface 28
Since the distance between A and the printing surface in the height direction can be made constant, the accuracy of image quality can be made constant regardless of the type of paper.

Here, as shown in FIG.
On one end side of the movable rib 42, inclined surfaces 36A and 42A inclined downward are formed, respectively, and are arranged on the guide surface 32 side.

The fixed rib 36 and the movable rib 42 have the inclined surface 3
By forming 6A and 42A, the sheet conveyed following the guide surface 32 is smoothly guided onto the platen 30. In addition, the movable rib 42 further includes an inclined surface 4.
2A makes it easier for the movable rib 42 to sink into the recess 40.

On the other hand, as shown in FIGS. 1 and 4, a suction device 61 is provided below the platen 30, and the platen 30 and a suction fan 60 provided in the suction device 61 are provided.
Is covered by a duct 62. A plurality of suction holes 64 are formed in the platen surface 30A, and a suction fan 60 generates a negative pressure on the platen surface 30A.

For this reason, the paper conveyed on the platen 30 is sucked through the suction holes 64 and is conveyed in a state in which the plain paper 43 comes into contact with the top surface of the fixing rib 36 as shown in FIG. The distance between the plain paper 43 and the nozzle surface 28A of the recording head 28 in the height direction is always constant.
Therefore, the printed image is not disturbed.

Further, even if the surface of the plain paper 43 swells due to the ink ejected on the plain paper 43 and is wavy,
The platen surface 30A is moved by the suction fan 60 (see FIG. 4).
Therefore, the swollen portion is absorbed by the height difference between the top surface of the fixing rib 36 and the platen surface 30A. Therefore, the plain paper 43 does not rise to the recording head 28 side, and the nozzle surface 28A does not rub the plain paper 43.

As shown in FIG. 6, the envelope 58 is conveyed in the movable rib area 38, so that it is conveyed in a state of contact with the platen surface 30A. Therefore, the suction force is increased as compared with the case where the sheet is conveyed in a state of being in contact with the top surface of the fixing rib 36, and the rising of the envelope 58 can be suppressed.

By the way, as shown in FIGS. 1 and 2, a plurality of transport rollers 66 are arranged at a predetermined interval on the downstream side of the platen 30. The transport roller 66 is rotatably supported by the side plate 10A of the paper feeding device 10, and a driving force is transmitted by driving means (not shown).

A plurality of star wheels 68 are disposed opposite to the transport roller 66.
8 is rotatably supported by a shaft 70,
6 can be driven. For this reason, the sheet that has passed over the platen 30 is transported between the star wheel 68 and the transport roller 66 and is discharged from the paper feeder 10.

The present invention is not limited to this embodiment. Further, the present embodiment may be applied to an image recording apparatus that inverts and discharges a sheet.

[0073]

According to the present invention, the nozzle surface of the recording head that slides on the platen does not rub against the envelope. Thus, it is possible to prevent the failure of the recording head due to the rubbing of the nozzle surface. Further, since the distance in the height direction from the nozzle surface to the printing surface can be made constant, the accuracy of image quality can be made constant regardless of the type of paper.

According to the third aspect of the present invention, the area of the movable ribs is minimized to increase the area of the fixed ribs, thereby maintaining the accuracy of image quality when conveying plain paper. According to the fourth aspect of the present invention, even if the plain paper slightly bends due to the sinking of the movable rib, the image quality is not affected by using the stiffness of the plain paper by transporting the both ends with the fixed ribs. The amount of deflection can be suppressed within the range.

According to the fifth aspect of the present invention, the end of the envelope body is prevented from engaging with the region of the fixing rib. According to the sixth aspect of the invention, when the plain paper is transported, the distance between the nozzle surface of the recording head and the printing surface is not varied between the area of the fixed rib and the area of the movable rib. According to the seventh aspect of the invention, the curl of the leading end of the recording medium conveyed from the conveying roller pair is suppressed, and the recording medium is reliably guided to the platen.

According to the present invention, the recording medium can be smoothly guided to the top surface of the fixing rib. In addition, in the case of plain paper, the leading end can be prevented from curling toward the recording head, and in the case of an envelope, the recording medium pressing member can reliably press the sheet against the platen.

According to the ninth aspect of the present invention, the distance between the printing surface of the recording medium and the nozzle surface of the recording head is always constant, so that the printed image is not disturbed. Also,
Since the recording medium does not rise to the recording head side,
The nozzle surface is not rubbed by the recording medium. Further, in the case of an envelope, since it is conveyed in a state in which it is in contact with the upper surface of the platen, the suction force is higher than in the case where it is conveyed in a state in which it is in contact with the top surface of the fixing rib, and the recording medium is The lifting can be suppressed.

According to the tenth aspect, the mechanism is simple. According to the eleventh aspect, the movable rib is prevented from sinking by the plain paper having less stiffness than the envelope body. In the twelfth aspect of the invention, the amount of sinking of the movable rib is ensured to absorb the thickness of the envelope, so that the nozzle surface does not rub the envelope when the envelope is transported.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a paper feeder provided with a paper feed mechanism according to the present embodiment.

FIG. 2 is an explanatory diagram showing a paper feeding device provided with a paper feeding mechanism according to the embodiment.

FIG. 3 is an exploded perspective view showing a movable rib of the paper feeding mechanism according to the embodiment.

FIG. 4 is a side sectional view showing a movable rib of the paper feeding mechanism according to the embodiment.

FIG. 5 is a front view showing a state of a movable rib when plain paper is conveyed by the paper feeding mechanism according to the embodiment.

FIG. 6 is a front view illustrating a state of a movable rib when an envelope is conveyed by the paper feeding mechanism according to the embodiment.

7A illustrates a state in which plain paper is nipped and conveyed by a conveying roller and a pinch roller of the paper feeding mechanism according to the embodiment, and FIG. 7B illustrates a state in which the upper surface of the plain paper is regulated by a paper pressing member. (C) shows a state where plain paper is guided onto the platen.

FIG. 8A illustrates a state in which an envelope is nipped and conveyed by a conveyance roller and a pinch roller of the paper feeding mechanism according to the embodiment, and FIG. 8B illustrates a state in which the upper surface of the envelope is pressed by a paper pressing member. (C) shows a state in which the movable rib has sunk into the concave portion via the envelope by the pressing force of the paper pressing member.

FIG. 9 is an explanatory view showing a conventional paper feed mechanism.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Paper feeder 20 Recording member press member (paper press member) 28 Recording head 30 Platen 30A Platen surface 34A Platen surface 34 Fixed rib area 36 Fixed rib 38 Movable rib area 40 Depression (long hole) 42 Movable rib 46 Engagement piece (Stopper) 50 Claw (stopper) 54 Coil spring (biasing means (spring)) 60 Suction fan (suction means) 61 Suction device (suction means) 62 Duct (suction means) 64 Suction hole P Registration reference position Q Registration reference position

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C058 AB17 AB22 AC07 AC11 AD01 AE11 AF20 AF21 AF31 AF38 AF44 DA11 DA38 2C059 BB06 BB11 BB15 BB21 DD08 DD09 DD13 3F049 AA01 AA10 DA12 FB00 LA07 LB03 3F101 FA01 FB14 FC07

Claims (13)

[Claims] A recording head from which ink is ejected; a platen arranged to face a movement trajectory of the recording head, and on which a recording medium is transported; and a top surface of the platen extending in a transport direction of the recording medium. And a plurality of fixing ribs arranged at predetermined intervals in a direction orthogonal to the transport direction, and extending on the upper surface of the platen in the transport direction of the recording medium, and in a direction orthogonal to the transport direction. And a plurality of movable ribs which are arranged at predetermined intervals and are pushed down by the recording medium to sink. 2. The apparatus according to claim 1, wherein the movable rib includes an urging means for urging the movable rib toward the recording head, and a stopper for restricting an amount of movement of the movable rib. Paper feed mechanism according to 1. 3. The paper feed mechanism according to claim 1, wherein an area in which the movable rib is disposed has a width substantially equal to a width of an envelope which is one of the recording media. 4. The paper feed mechanism according to claim 2, wherein the fixed ribs are arranged on both sides of a region where the movable ribs are arranged. 5. The paper feeder according to claim 3, wherein the registration reference position of the envelope is an end of a region where the movable rib is disposed, and the envelope is conveyed within the region. mechanism. 6. In a state where the recording medium is not conveyed,
The paper feed mechanism according to any one of claims 1 to 5, wherein a top surface of the movable rib and a top surface of the fixed rib have the same height. 7. A transport roller pair disposed on an upstream side of the platen for nipping and transporting the recording medium, wherein a posture is held between the transport roller pair and the platen by pressing an upper surface of the recording medium. 7. The paper feed mechanism according to claim 2, further comprising a recording medium pressing member for guiding to a platen. 8. The position of the leading end of the recording medium pressing member is 0.2 mm to 0.5 m below the top surface of the fixing rib.
8. The paper feeding mechanism according to claim 7, wherein the height of the paper feeding mechanism is m higher. 9. A plurality of suction holes provided on an upper surface of the platen facing a movement trajectory of a nozzle surface provided on the recording head, and suction means for sucking the recording medium through the suction holes. The paper feed mechanism according to any one of claims 1 to 8, further comprising: 10. The urging means is a spring, and when the envelope is conveyed, the movable rib has a spring force to sink, and the stopper protrudes from a long hole formed in the platen surface. The paper feed mechanism according to any one of claims 2 to 9, wherein the pawl portion is formed integrally with the movable rib, and is a claw portion that comes into contact with the back surface of the platen to limit the amount of movement of the movable rib. 11. The biasing means is a spring, and the movable rib is pressed by a pressing force of the recording medium pressing member.
The paper feed mechanism according to any one of claims 7 to 9, wherein the movable rib has a spring force that sinks through the envelope body. 12. The printing apparatus according to claim 11, wherein an upper surface of the platen in a region where the movable rib is disposed is formed more apart from a nozzle surface of the recording head than an upper surface of the platen in a region where the fixed rib is disposed. The paper feed mechanism according to any one of claims 1 to 11, wherein: 13. An image recording apparatus comprising the paper feed mechanism according to claim 1. Description: